Map shows concentration of ozone at 10 meters above ground (ground-level ozone). Low level ozone is an atmospheric pollutant. It is not emitted directly by car engines or by industrial operations, but formed by the reaction of sunlight on air containing hydrocarbons and nitrogen oxides that react to form ozone directly at the source of the pollution or many kilometers downwind. Model has lower resolution than reality. Therefore model cannot differentiate, for instance, the pollution near a highway or in a city center.